Comparison of efficacy of intrathecal dexmedetomidine and magnesium sulfate as an adjuvant to 0.5% hyperbaric bupivacaine in patients undergoing infraumbilical surgeries under spinal anesthesia

Abstract

Background: Adjuvants in spinal anesthesia extends not only the duration of surgical anesthesia but also provides postoperative analgesia. This study aimed at comparing efficacy of intrathecal dexmedetomidine and magnesium sulfate as an adjuvant to 0.5% hyperbaric bupivacaine in various infraumbilical surgeries. Materials and Methods: 120 patients belonging to American Society of Anesthesiologists (ASA) physical status I or II aged 18 to 65 years of either sex were enrolled and randomly allocated into two groups. Group D (n = 60) received intrathecal bupivacaine (hyperbaric) 0.5%, 12.5 mg (2.5 ml)+dexmedetomidine 5 μg (0.5 ml) while Group M (n = 60) received bupivacaine (hyperbaric) 0.5%, 12.5 mg (2.5 ml) + magnesium sulfate 75 mg (0.5 ml) = 3 ml. Onset of sensory and motor block, time to reach peak level of sensory block, time to two segment regression, duration of sensory and motor block, duration of analgesia, sedation score, hemodynamic changes, and side effects were noted. Results: Onset of sensory and motor block were significantly faster in Group D (2.78 ± 0.34 min and 3.73 ± 0.43 min) compared to Group M (6.47 ± 0.43 min and 7.72 ± 0.48 min); (P 0.05). Conclusion: Dexmedetomidine (5 μg) leads to faster onset as well as prolonged duration of both sensory and motor block, prolonged duration of postoperative analgesia in comparison to magnesium sulfate (75 mg).